This document discusses an adaptive management strategy for reducing PCBs in storm water runoff. It provides background on PCB properties, analytical methods for measuring PCBs, and considerations for conceptual site models. Early results from Phase 1 show that preventing erosion and reducing suspended solids is more effective for lowering PCB discharges than hydraulic detention alone. The adaptive management process involves evaluating sample data, reviewing storm water facilities, formulating solutions, designing and constructing improvements, and collecting additional data.

1. An Adaptive
Management
Strategy for
Reducing
PCBs in Storm
Water
April 5, 2016
Environment Virginia Symposium
Robert Wallace, P.E.
A. Currie Mixon, P.E.

2. Aqueous Analyses
mg/L
1E-6
ng/L
1E-12
pg/L
1E-15
μg/L
1E-9
ppm of ppm
PCBs and Analytical Methods
g/L
1E-3
Method 8082
Not congener-
specific
$100-$200/sample
Method 1668
Measure all 209
congeners, sum
$750-$1000/sample
Detection Limit of Method 1668Detection Limit of Method 8082
• 209 possible congeners
• Chemical stability
• Thermal stability
• Bioaccumulative
-2 -3-1 -5 -6-4 -8 -9-7 -11 -12-10 -14 -15-13
Units for typical storm
water pollutants

3. Property Description of PCBs
Organic carbon
partitioning
Strongly hydrophobic (sorbs to carbon)
Particle size 90% of PCBs associated with particles ≤ 20 µm
Aqueous Solubility 0.03– 0.6 mg/L (Arochlors) – 30,000 to 600,000 ng/L
Biodegradability Very low to none
• Vast majority of PCB mass
associated with suspended solids
• Preventing erosion (reducing
suspended solids) is more
effective than hydraulic detention
for reducing PCB discharges
Conceptual Site Model Considerations
Photo of Phase 1
𝑀𝑀𝑃𝑃𝑃𝑃𝑃𝑃 = (𝐶𝐶𝐴𝐴𝐴𝐴.,𝑃𝑃𝑃𝑃𝑃𝑃∗ 𝑄𝑄𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵) + (𝐶𝐶𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆,𝑃𝑃𝑃𝑃𝑃𝑃∗ 𝑇𝑇𝑇𝑇𝑇𝑇 ∗ 𝑄𝑄𝑆𝑆𝑆𝑆)

4. Adaptive Management for Storm Water
0
100
200
300
400
500
600
700
800
Pre-Construction Avg. Post-Construction Avg.
PCBConcentration(ng/L)
Outfall 003
Outfall 004
Maxima
Minima
Phase 1 Early Results
Evaluate
sample data
Review facility
storm water
management
Formulate
solution
(PMP)
Design &
construct
Collect data

5. Conceptual Facility Best Management Practices
Options
Phase 1
Construction